leitner



(No Model.) a Sheets-Sheet 1.

H. LEITNER.

1 ELECTRIC ARC LAMP. No. 590,725. Patented Sept. 28, 1897. 1 739.]. (D I(No Model.) 3 SheetsShet 2.

H. LEITNER. ELECTRIC ARC LAMP.

No. 590,725. Patented 88 112.28, 1897.

(NoModeL) 3 SheetsSheet 3.

H. LEITNER. ELECTRIC ARC LAMP No. 590,725. v Patented'Sept. Z8,1897.

Nrrnn STATES PATENT anion.

HENRY LEITNER, OF LONDON, ENGLAND.

ELECTRIC-ARC LAM P.

SPECIFICATION forming part of Letters Patent No. 590,725, datedSeptember 28, 1897.

Application filed April 16, 1897. Serial No. 632,442. (No model.)

To all whom it may concern:

Be it known that I, HENRY LEITNER, phi-, lologist, a subject of theQueen of Great Britain and Ireland, residing at 207 Piccadilly, London,England, have invented certainnew and useful Improvements in theConstruction of Arc-Lamps, of which the following is a specification.

This invention relates to improvements in the construction of arc-lamps,and has for its object to provide a simple arrangement which will insurea constant feed for the carbon and one which will at the same timeregulate the arc with great accuracy and give a constant focus.

The device I propose to employ for this purpose consists of two coils orsolenoids, one coil being in series with the lamp and the other inshunt-circuit. These coils are placed one above the other or side byside, and a central iron core is placed within the coils aboutone-quarter greater in length than one of the said coils when the latterare arranged one above the other. This core is connected to themechanism by which the carbons are adjusted, and in order to magnify orincrease the motion so that a small distance traveled by the core willmove the carbons a much greater distance a line or connection from thecore passes over a small wheel carried on a shaft or spindle at the topof the lamp. On each side of the spindle larger wheels are employed,connections passing, respectively, to the upper and lower carbons beingwound on the said wheels. The connections are wound in oppositedirections, so that on turning the spindle in one direction the carbonsare caused to approach one another and on turning in the reversedirection they are separated.

To allow for the different rate at which the upper and lower carbonsburn in the case of continuous currents, the wheels or drums con nectedwith the carbons are of correspondingly different sizes, insuring aconstant focus for the light.

To raise and lower the core, and consequently to adjust the carbons, thecoils are made in a peculiar manner. Instead of forming simple coils,both the series and shunt coils are made in sections and provided with anumber of con tact-bars insulated from each other, but placed as closetogether as possible. I prefer to use about four of these contact-barsto the inch; but they may be arrangedmore closely if found desirable.The arrangement somewhat resembles the cominutator of a dynamo, and toeach bar one of the coils on the solenoid is connected, the wire betweeneach section, instead of being wound directly on the bobbin, being drawnout or looped and connected to the bar. The core is thus divided into aseries of single coils or sections corresponding to the number ofcontact-bars, each section being capable of acting independently, butconnected to the next. On connecting up any two of these bars thecurrent will be caused to pass through those sections only which liebetween the bars v thus connected, the rest of the coil beinginoperative.

To form the contact where the coils are placed one above the other, aframe is em ployed carried in suitable bearings and connected to thecore. On this frame two contact pieces or brushes for each of the twocoils are fitted insulated from each other, and the two pairs are placedat corresponding points With relation to the coils to which they areapplied. The complete frame and brushes move along with theiron core,the ends of the latter being situated between the two brushes of eachpair. here the solenoids are side by side, two frames independent ofeach other are used, each being connected to its core. The coils pull inopposite directions, and the Winding on the shunt-coil is arranged sothat the pull on the central core balances the pull from the series coilwhen the carbons are in the best position for the are.

On the current being turned on, supposing that the carbons are incontact, the current will pass only through the series coil or throughthat section of it situated between the two brushes, the shunt-coilbeing practically short-circuited. As the core is not situatedcentrallywith relation to the part of the coil rendered active, it willbe moved, carrying the frame along with it and shifting the brushes toanother set of bars. This instantly separates the carbons and at thesame time, owing to the increased resistance, allows the current to passthrough the shunt-coil, pulling the core in the opposite direction.

ICO

If the carbons are apart before the current passes, the action isreversed, bringing the carbons together. The core and connecting partsmove until the resistance of the arc causes the current passing throughthe series and shunt coils to balance, when the parts become stationary.As the carbons gradually burn away and thus tend to lengthen the are andincrease the resistance the balance of the current is disturbed, but isinstantly righted by the brushes moving so as to include dill'erent setsof coils, the action being continuous and allowing for very slightvariations of current. Any irregularity in the carbons or in their rateof burning is allowed for, the action entirely depending on the current,and at the same time no complicated parts are required, the connectionsbeing all of the simplest kind. With coils constructed in this peculiarmanner an even and strong pull is obtained, as the core is always in thesame position relatively to the active solenoid and always at the mostadvantageous point. At the same time a much greater travel is obtainedfor the same length of coil than with coils wound in the ordinarycontinuous manner, as in the latter case the pull ceases on the coretaking up a central position. There is also no jerking when the currentis turned on.

In order that the invention maybe more clearly understood, reference ishad to the accompanying sheets of drawings, in which Figure 1 shows oneform of my apparatus in side elevation. Fig. 2 is an elevation at rightangles to Fig; 1. Fig. I is a plan, and Fig. lshows a modifiedarrangement with the coils placed side by side.

Referring to Figs. 1,2, and 3, the series and shunt coils A and B areplaced one above the other, the series coil A in the arrangement shownbeing at the top. Both these coils are, as shown, wound in a number ofdifferent sections, each section being separately connected to one ofthe contact-bars a or Z), the contact-bars a belonging to the seriescoil and I to the shunt. The wire in each case after forming a loopconnected to the corresponding bar continues to form the next section ofthe coil, so that while the sections are inde pendent all those in onecoil are permanently connected up in series. The contacts a and h aresupported on bars 0, which may be of insulating material or providedwith an. insulating-surface on which the contacts are placed. Each baris insulated from the next, so that a current can be introduced throughany one of the contacts independently of the others. To form a circuitthrough the series coil, the brushes 1) are employed, thesebeingpreterably made of l. shape and hinged at (Z to an arm E, screwedor otherwise fixed to a block c of insulating material. A spring (Zbears on the top of the brush, so that it is caused to press on thecontacts (L. The two brushes shown are separated from each other by aninterval. sufficiently large to include several of the sections of thecoil. The connections F and F pass to these brushes rcspectively fromthe main and to one ol the carbons. At the same time the ends of thecoils are connected to the same terminals. On the current passingthrough the brushes, owing to all the sections covered by them beingshort-circuited, the current will only pass through that portion of thecoil situated between the two brushes, but should they by any accidentbe momentarily raised from. the surface of the contacts the circuit willnotbc broken, but will simply pass through the complete coil. Alsoshould the connection to either of the brushes be broken the currentwill not be impeded in any way, as it will proceed through the brushwhich shortcircuits all the sections, thus entirely obviating any dangerof the parts getting out oi. order.

The arrangement is precisely similar tor the shunt-coil, brushes 1)being provided sup ported by the insulating-blocks These blocks arecarried on the frame ll, this frame consisting of two arms or rodsextending on each side of the coils, the blocks 0 tor the shunt-coilbeing placed lower than those for the series coil, but in correspondingposition with respect to the sections or contact-bars Z). The strengthof the series and shunt coils can be relatively varied to any requiredextent by shifting the position of the brushes or contact-pieces on theframe. This is an important feature of the special method of windingemployed. The frame is provided with a central rod 71, which :isconnected to the central iron core .1, this core extending within thecoils A and l and being preferably slightly longer than one ot thecoils. The ends of the core are situated within the excited sections ofthe coils, the core being fixed at the proper height with. respect tothe frame. The frame, core, and brushes are thus all fixed relatively toone another, so that when the core moves the other parts willcorrespondingly move, shifting the positions of the active sections.

From the upper end of the core a cord or connection K extends, passingover the drum or wheel 7i: on the shaft L. This shaft or spindle istixed at the top of the lamp and the wheel or drum 7c is placed at thecenter. At each side of this wheel the drums N. and M are placed, overwhich the connections on and m are wound in opposite directions, theseconnections passing, respectively, to the supports for the upper andlower carbons G and G. Thus on the core moving the spindle will berevolved and the drums M and M. will turn, causing the carbons toapproach toward or reeede from each other. The weight of the parts willbe sullicieut to bring the carbons together when the core is moved, soas to lessen the pullv on the connection K, the magnetic pull on thecore separating the carbons, so that the core only requires to exercisea direct pull in one direction.

ICO

Referring to Fig. 4, the same principle is employed, but instead of thecoils being placed one above the other the series and shunt coils A andB are placed side by side. Two frames II are employed and also two coresJ and J one for the series and the other for the shunt coil. These coresare considerably shorter than the single one employed in the arrangementbefore described, and each core is provided with a connection K, passingto a wheel or drum 7c on the shaft L. These connections are wound inopposite directions, so that one cord descends as the other rises, bothacting on the spindle and causing it to turn in correspondingdirections. The drums M and M are in this case placed at the center ofthe spindle and the connections to the carbons may pass between the twocoils. In this arrangement only one side of the frames H is actuallyused to carry the contact-strips, the other side bearing against theside of the coil or other suitable part in order to keep the frame in alevel position. The arrangement of coils placed side by side possessesthe advantage that there is a pull in both directions, the action thusbeing quite independent of the weights of the various parts. The pull onthe core belonging to the series coil always tends to move the carbonsapart and that on the other core to bring them together. The pull onboth cores is in a downward direction and is the same at all points, sothat even at the beginning of the operation when the lamp has beensupplied with new carbons and the core of the series coil is almost atits lowest point it will use the small travel remaining to it with fullforce to draw the carbons apart. The connections to the carbons are thusalways kept taut, as there is always a pull from both cores.

Instead of forming the contact-strips of considerable length, so as toshort-circuit most of the sections of the coil, I may make them ofsufficient size only to cover two of the contact-bars at one time, asshown in Fig. t. Connections are made in this case only to the brushesand not to the ends of the coils, so that the current .will pass asbefore only through those sections situated between the brushes. Thisarrangement is similar in all other respects to that already describedand the action of the coils is precisely the same.

hat I claim as my invention, and desire to secure by Letters Patent, is

1. In an improved feeding mechanism for arc-lamps, the combination witha series and shunt coil constructed from a number of independentsections and contact-bars insulated from each other and connected toeach of the said sections, of an iron core in the said coils, a frameconnected to the said core and brushes on the frame for each coil, thesebrushes bearing on the contact-bars leading the current throughcorresponding sections, and connections to the carbons causing them tomove with the core, substantially as described and for the purposesspecified.

2. In feeding mechanism for arc-lamps, the combination of a series andshunt coil, each coil wound in independent sections, and two sets ofcontact-bars one for each coil, each contact-bar being connected to asection of the coil to which it belongs, an iron core within the saidcoils, a frame to which the core is attached and two sets of brushes oneset for each coil, bearing on the contact-bars, with a spindle having adrum or wheel a connection from the core passing over the said drum, andtwo drums or wheels on the same spindle connected respectively to theupper and lower carbons, substantially as and for the purposesspecified.

3. In feeding mechanism for arc-lamps, the combination of a series andshunt coil one above the other, each coil being wound in a series ofindependent sections, and two sets of contact-bars one to each coil,each contactbar being insulated from the next and connected to one ofthe said contacts with a central iron core placed within the said coils,a frame extending on each side of the coils carrying the core, two setsof brushes carried by the sides of the frame bearing on the contact-.bars leading the current through a constant number of sections, andconnections from the core to the carbons causing them to move with thecore and frame, substantially as and for the purposes specified.

4. In feeding mechanism for arc-lamps the combination of a series andshunt coil placed one above the other each coil woundin a number ofindependent sections, two sets of contact-bars one for each coil eachcontact-bar being connected to a section, a central iron core, a framecarrying the core extending on each side of the coil, and two sets ofbrushes on the frame, bearing on the contact-bars, with a spindle at thetop of the lamp, a drum at the center of the said spindle, a connectionpassing over the said drum to the core, side drums or wheels on the samespindle and connections, wound in opposite directions on these wheels,passing to the carbon-holders causing them to move with the core andframe substantially as described and shown and for the purposesspecified.

5. In feeding mechanism for arc-lamps, the combination with a series anda shunt coil, each coil wound in a number of independent sections, and aset of contact-bars for each coil connected independently to thesections, of an iron core, a frame carrying the core, two sets ofbrushes, adapted to bear on the contact-bars, short-circuiting all thesections except those in the gap between the brushes, electricalconnections to the brushes and to the end of the coils, and connectionsfrom the core to the carbons, substantially as and for the purposesspecified.

6. In feeding mechanism for arc-lamps, the combination of a series andshunt coil placed side by side and wound in independent sections, and aset of contact-bars for each coil, each bar connected to a section, witha central iron core in each coil, a frame connected to each core,brushes on each frame bearing 011 the contact-bars and connections fromthe cores to the carbons, substantially as described and shown and forthe purposes specified.

'7. In feeding mechanism for are 1an1ps the combination with a seriesand a shunt coil wound in a series of independent sections and placedside by side, a set of contact-bars for each coil each bar connected toa section, of

